1. Field of the Invention
The present invention relates to a radiation image information reading apparatus for reading radiation image information stored in a stimulable phosphor panel that is held in a cassette and thereafter erasing remaining radiation image information stored from the stimulable phosphor panel.
2. Description of the Related Art
There are known radiation image information reading apparatus that employ a stimulable phosphor panel which stores a part of radiation energy applied thereto and, when subsequently exposed to applied stimulating rays such as visible light or the like, emits light in proportion to the stored radiation energy.
The radiation image information reading apparatus have a cassette loading unit for loading a cassette which holds a stimulable phosphor panel that is storing the radiation image information of a subject such as a human body or the like, a reading unit for applying stimulating rays to the stimulable phosphor panel to read the stored radiation image information therefrom, and an erasure unit for applying erasing light to the stimulable phosphor panel from which the radiation image information has been read to erase remaining radiation image information from the stimulable phosphor panel. After the remaining radiation image information has been erased, the stimulable phosphor panel is held in the cassette and discharged from the radiation image information reading apparatus for reuse (see Japanese Laid-Open Patent Publications Nos. 2002-156716, 6-43565, and 2001-503880 for details).
The stimulable phosphor panel comprises a support and a stimulable phosphor layer disposed on the support for recording radiation image information therein. In order to obtain desired light emitted from the stimulable phosphor panel, it is necessary that the cassette holding the stimulable phosphor panel therein be properly faced and loaded. In addition, the cassette should also properly be oriented and loaded to allow the stimulable phosphor panel to be removed from the cassette or to read the stored radiation image information in a correct orientation from the stimulable phosphor panel.
According to the radiation image information reading apparatus disclosed in Japanese Laid-Open Patent Publication No. 2002-156716, a code storage element is disposed on the cassette and a code reading means for reading a code stored by the code storage element is disposed in the cassette loading unit. If the code reading means fails to read a code from the code storage element or the code reading means reads an unidentifiable code from the code storage element, then it is judged that the cassette is loaded in error, followed by the display of an error message, and the cassette is prevented from being further introduced into the radiation image information reading apparatus.
When a cassette loading error is detected, the cassette will not be introduced into the radiation image information reading apparatus and will not be processed unless the operator takes some action to remedy the fault. The radiation image information reading apparatus disclosed in Japanese Laid-Open Patent Publication Nos. 6-43565 and 2001-503880 is not arranged to detect how the cassette is loaded. Therefore, if the cassette is loaded in error, then any processing on the cassette is interrupted or the cassette is wrongly processed. At any rate, unless the operator corrects the improperly loaded state of the cassette, a time loss tends to be caused by the interruption of the cassette processing or the wrong processing of the cassette.